This invention has to do with swimming pool covers and like covers for bodies of water or other areas desired to be protected from the environment, e.g. against evaporative loss, dilution through rain exposure, or loss of heat such as may be encountered in swimming pool maintenance. The invention further provides a positive heating device for swimming pools or other bodies of water, including domestic water supplies, by incorporating in the cover solar radiation responsive wall portions adapted to transfer heat to water in contact therewith. In particular aspects, the invention provides novel and highly advantageous means for alternately deploying and storing the pool cover in an expeditious and efficient manner requiring a minimum of manual effort, and free from cumbersome apparatus and mechanical interference with pool enjoyment. Cf. U.S. Pat. No. 3,885,255 to Vorbach et al.
The present invention, while termed a cover, is in a more specific sense directed to structure enabling the deployment and/or storage of sheet material. The sheet material during these periods may be employed as a cover for a swimming pool to prevent heat loss, may protect athletic fields or like areas from the elements, or may be merely a conduit for air or other gas to be heated for another purpose, or may be the support for a solar heating apparatus. Thus, the cover herein is to broadly construed as a structure having longitudinal and lateral extension which may be retracted into a furled condition on the one hand or extended fully or partly on the other.
With the foregoing in mind, the invention nonetheless will be described with respect to a highly advantageous use hereof, namely a swimming pool cover having the capability of solar radiation heating swimming pool water or other domestic water supply while protecting a swimming pool from incursions of contaminants such as leaves and dust, and at the same time inhibiting heat loss through water vaporization from the surface of the pool. As is well known, swimming pools are most comfortable when heated to slightly above the mean temperature encountered during the day. Indeed, it has been found that efforts to heat swimming pool water far in excess of the average daily mean temperature is disproportionately costly and in these energy conscious times, wasteful of a natural resource since most swimming pool heating heretofore has been accomplished by use of natural gas. Swimming pool covers without solar heating capability have been devised and marketed and have in large extent comprised a single reinforced sheet of plastic or canvas material which is extended over the pool surface, sometimes resting thereon, and tied at its perimeter. Such covers have been used for pool safety to prevent inadvertent falling into the pool, as well as to keep contaminants from entering into the pool. Such covers are particularly popular where the pool use is infrequent as in northeastern climates where a pool cover might remain on the pool for months at a time. In more pleasant climates, pool use is more frequent and the presence of covers is not favored because of the difficulty of removing and re-establishing covers upon the occasion of each pool use. Accordingly, some have proposed covers which lack the safety benefits of integral pool covers and which comprise a series of floats which can be formed into a pool cover and readily removed in whole or in part for pool use. Even these devices are cumbersome, however, particularly when weighted with water. The heat conservation aspects of swimming pool covers are preserved however by these devices, and some incorporate solar energy powered heaters. See U.S. Pat. Nos. 3,893,443 to Smith and 3,072,920 to Yellott.
Other types of sheet material structures designed primarily for solar heating of water passing thereacross may be adapted to swimming pool cover use, but the problem remains of ease of establishment and removal of the cover before and following use. In the absence of great convenience, the consumer will not tolerate a swimming pool cover, be it energy efficient, cost reducing, and safety useful; removal and re-establishment cannot be troublesome. Cf. U.S. Pat. Nos. 3,541,615 to Myrtha; 3,747,132 to Foster; 3,927,427 to Aine; and 3,574,979 to Chan.
It is, accordingly, an object of the present invention to provide a cover for swimming pool or like surface which is easily extended and retracted and which may incorporate solar heating features for the heating of pool water or other domestic water supply. Other objects of the invention include self-retraction capabilities in the cover, reelless furling of the cover, self-support of the cover when extended, solar heating capability in the cover for water in contact therewith, and the use of low cost, readily available materials which are deployable by one person without strain or undue time consumption.